A sexually transmitted infection (STI) is caused by viruses, bacteria, fungi, or parasites that can be contracted through sexual activity. You might also hear the term sexually transmitted disease (STD). While people often use STI and STD interchangeably, there’s a subtle but important difference. An STI refers to the infection itself, while an STD refers to the disease that develops as a result of the infection, usually with noticeable symptoms. Public health focuses on preventing infections before they become diseases, which is why health organizations often prefer the term STI. However, both terms are used and understood.
Types of STIs
There are many different types of STIs. Some of the most common include:
- Chlamydia
- Gonorrhea
- Genital Herpes
- Human Papillomavirus (HPV)
- Syphilis
- Trichomoniasis
- HIV
Signs and Symptoms of STIs
A significant aspect of STIs is that many don’t present any noticeable symptoms, or symptoms might be very mild. This means a person can have an STI and be unaware of it. This lack of obvious symptoms is why regular STI testing is crucial for sexually active individuals. If you receive a positive STI diagnosis, it’s important to know that most STIs are treatable with medication, and some are completely curable.
How STIs Spread
STIs are primarily transmitted from one person to another through sexual contact. This includes vaginal, anal, and oral sex. While less common, some STIs can also spread through close physical intimacy such as skin-to-skin contact, particularly with genital contact.
Conditions Related to STIs
Certain health conditions are closely linked to sexual transmission. These can include pelvic inflammatory disease (PID), which is often a complication of untreated STIs like chlamydia and gonorrhea, and can lead to infertility.
It’s also worth noting that some diseases, like Zika virus, Ebola, and mpox, while can be spread through sexual contact, are more frequently transmitted through other means.
